Combined filter paper support and filtrate container

ABSTRACT

A container capable of functioning as a combined filter paper support and filtrate holder is disclosed which comprises a selfstanding body portion which narrows into a neck area which in turn flares outwardly to the upper lip. The size of the neck area and flared portion are selected so that they are capable of supporting a conical filter medium such as a folded piece of filter paper. The container is further adapted to be tightly closed by a flexible stopper having an exterior, downwardly extending protective skirt which extends over the lip area as well as the outside of the neck and flared portions.

United States Patent 1191 Eddleman et al.

[ Dec. 18, 1973 COMBINED FILTER PAPER SUPPORT AND FILTRATE CONTAINER [75] lnventors: Roy T. Eddleman, Beverly Hills;

Richard L. Schmitz, Diamond Bar, both of Calif.

[73] Assignee: Spectrum Medical Industries, lnc.,

Los Angeles, Calif.

22 Filed: Apr. 29, 1971 21 App]. No.: 138,617

[52] US. Cl 215/48, 23/292, 210/474, 215/1 R, 220/97 F [51] llnt. Cl B65d 39/00 [58] Field of Search 215/1 R, 1 C, 47, 215/48, 52; 23/292; 210/474, 497; 220/97 F; 222/572 [56] References Cited UNITED STATES PATENTS 1.718.897 6/1929 Dunbar et 11 D23,892 12/1894 Gulden..... 2l5/l R 3,37l,808 3/1968 Velt 215/52 2,978,142 4/1961 Novick 220/97 F 3,140,007 7/1964 Nettleshlp 220/97 F 334,415 6/1886 Shirley 215/1 R Mohn 215/31 UX 579,867 3/1897 Fenn t. 215/31 1,275,816 8/1918 Williamson et al. 215/47 2.583.162 1/1952 Verel 215/47 FORElGN PATENTS OR APPLICATIONS 1.051659 1/1967 Great Britain 215/48 1.112.313 3/1956 France 215/48 546,443 7/1942 Great Britain 23/292 Primary E.\aminer--Herbert F. Ross Assistant ExaminerStephen Marcus Attorney-Lyon & Lyon [57] ABSTRACT A container capable of functioning as a combined filter paper support and filtrate holder is disclosed which comprises a self-standing body portion which narrows into a neck area which in turn flares outwardly to the upper lip. The size of the neck area and flared portion are selected so that they are capable of supporting a conical filter medium such as a folded piece of filter paper. The container is further adapted to be tightly closed by a flexible stopper having an exterior, downwardly extending protective skirt which extends over the lip area as well as the outside of the neck and flared portions.

11 Claims, 5 Drawing Figures COMBINED FILTER PAPER SUPPORT AND FILTRATE CONTAINER BACKGROUND OF THE INVENTION The field of the invention is laboratory glassware and more specifically relates to laboratory beakers or flasks. Commonly used beakers are generally cylindrically shaped and have a stable base portion and an upper lip. The upper lip typically contains a pouring spout portion to facilitate the emptying of a fluid from the beaker into another container. Such beakers are commonly used to collect and contain a filtered liquid. Other related containers commonly used to collect and contain filtrates include Florence flasks, Erlenmeyer flasks and round-bottomed flasks. While beakers typically have cylindrical sides, flasks typically are greatly narrowed at the top to help contain liquids and to permit them to hold a stopper.

When one wishes to filter a liquid the most common procedure is to support a funnel above a container and a filter medium is then placed within the funnel and the liquid to be filtered is poured into the filter medium. There are various means for supporting the funnel a common one being a ring stand. It is also common to support the funnel on the upper lip of a flask. Of course, this decreases the stability of the flask and can lead to broken glassware.

Although cylindrical beakers have the advantage of being easy to clean, they are not readily adapted to be closed. Florence and Erlenmeyer flasks may be closed by the insertion of a cork or other stopper but because of their narrow neck area are difficult to clean and dry. The need for supporting a funnel on a ring stand not only requires the use of the cumbersome ring stand support but also the ring stand itself can collect foreign matter which can be brushed off its surface to contaminate the filtrate.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a container which is capable of supporting a filter medium and containing a filtrate.

It is another object of the present invention to provide a container which can be closed by a stopper.

It is yet another object of the present invention to provide a container and stopper combination which not only provides a liquid tight compartment, but also provides a container with an outer surface which is protected from contamination.

The present invention is for a container which has a base portion which permits the container to stand without support on a horizontal surface, a body portion for containing a liquid, a neck area adapted to be sealed by a flexible stopper and an upper flared portion shaped to support a conically folded filter medium. By this combination it becomes possible to filter a liquid and sealably contain the resulting filtrate through the use of a single piece of laboratory glassware and a stopper. The funnel and ring stand are no longer required and thus two potential sources of contamination are eliminated. The dimensions of the neck portion and the shape of the flared area are important features of the present invention. The neck area must be large enough to permit the ready entry of cleaning implements as well as stirrers, spatulas and the like. The neck portion must be small enough to be readily closed by a flexible stopper. The flared area must have a shape and an inside diameter which will support a conically folded filter medium such as a circular piece of filter paper which has been folded first along its diameter and secondly along the bisector of the resulting semi-circle. When such a sheet of circular filter paper has been thus folded, and opened it forms a cone having an angle of 60.

If the minimum size of the flared area is too large, the filter paper may fall through the flared area into the container. The upper lip of the container is preferably smaller than the outside diameter of the body portion to enable a stopper having a cylindrical, downwardly extending protective skirt to be placed thereover and the resulting stoppered container to have no greater size at the stopper than in the body portion.

BRIEF DESCRIPTION OF THE DRAWINGS of an alternate configuration of the container of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS For purposes of description the upper portion of the containers shown in the drawings are divided into a neck area and a flared area. That portion of the container which extends from the body portion inwardly to a minimum inside dimension will be referred to as the neck area. That portion which extends upwardly from the minimum inside diameter is referred to as the flared portion." In those instances when the container is shaped to have a cylindrical length along its minimum inside diameter the neck area will be referred to as that portion which extends upwardly from the body portion, through the cylindrical portion and to the point when the inside diameter increases.

Turning now to FIG. I, a container, generally indicated as 10 has a base portion 11 which extends from the intersections l2 and 13 of the base portion with a body portion 14. Although the body portion 14 shown in FIGS. l and 2 is cylindrical, it could be square, rectangular, triangular or the like.

The neck area" begins at intersection 15 and extends upwardly to the plane of minimum inside diameter 16. The flared area" extends upwardly from 16 ending at the upper lip 17. The upper lip 17 may contain a spout I8 and furthermore may contain two or more spouts although only one is shown in the drawings. The spout 18 should not extend downwardly to the plane of minimum inside diameter, however, since this might interfere with the ability to close the container with a cylindrical stopper.

Although the body portion 14 may be in a shape other than a cylinder, it is preferable that the area near the plane of minimum inside diameter 16 be circular along any horizontal plane. In this way, a stopper having a frustro-conical shape can form a tight seal with the container. The shape at the upper lip and the shape near the intersection 15, of course, need not be circular along the horizontal plane.

A conical filter medium is shown resting against the flared portion of the container 10. For clarity and description this filter medium will often be referred to as filter paper but, of course, need not be fabricated from paper but may instead be formed from another porous medium. Laboratory filter paper is most commonly supplied in flat circular sheets. These are formed into generally conical shapes by a two-step folding operation. The first step is to fold the circular sheet along the diameter to form a doubled semi-circle. The second folding step is made along the bisecting radius of the semi-circle. The paper is then opened up and can be made to form a cone whose opposite sides form an angle of 60 with one another. The angle of the conical filter medium 20 of FIG. 1 is indicated by the reference character a.

It is the function of the flared area to support the conical filter medium in such a manner that it neither falls through the flared area nor tips over after it has been filled with a liquid. In order to perform this dual function, the shape and dimensions relative to the filter paper are of extreme importance. It has been found that a frustro-conical shape such as that shown in FIG. 4 and discussed below is satisfactory. It has further been discovered that the shape formed by the rotation of an are about the central axis of the container is particularly effective in performing this dual function. A slight misalignment of the conical filter medium is readily supported by such a shape and the support is such that it does not tend to crease or indent the filter medium. As discussed herein, the shape of the flared portion is referred to exclusive of the spout or spouts.

The radius of curvature of this are is another important feature of the present invention. If the radius is too small, the filter medium can readily be tipped over. If it is too large, the filter paper will be supported only at the lip of the container. It has been found that a radius of curvature between one-fourth and two-thirds of the minimum inside diameter is satisfactory. A ratio of 0.44 has been found particularly effective.

It has been found that the minimum inside diameter 21 of the neck area should be at least two-fifths of the maximum outside diameter of the body portion but no more than three-fifths of this dimension. A particularly effective container results when this ratio is about onehalf. The major part of the neck area and the flared portion of the container shown in FIG. 1 has a crosssectional shape of an arc of a circle having a radius 23.

Turning now to FIG. 2, spout 18 is located in the container lip 17 and functions to facilitate pouring material from the container. The conical filter medium 20 is not shown in FIG. 2. Although the shape of the spout 18 is conventional it should not extend to the plane of minimum inside diameter 16 or into the neck area since it might then interfere with the tight closing of the container.

Turning now to FIG. 3, a stopper, generally indicated at 30, is shown placed in the upper part of the container 10. The stopper is formed from an outer piece 31 made from a relatively hard material such as polypropylene. This outer piece 31 has a downwardly extending protective skirt 32 formed integrally therewith. The stopper 30 has a central flexible portion 33 which further has a hollowed out area 34 to further increase the flexibility of the central portion. An outer protrusion 35 extends around the lower edge of the flexible portion 33 to help hold the stopper in the neck area of the container. Note that the stopper seals the container by contacting with the neck area rather than with the flared portion. It is thus important that the neck area be circular at the point at which it contacts outer protrusion 35. In this way the stopper may be rotated to facilitate its removal and insertion while still forming a tight seal. The upper portion of outer piece 31 is indented to form a dish-shaped surface 36. Dish-shaped surface 36 is formed in the same shape as base portion 11 of the container shown in FIG. 1. In this way several stoppered containers may be readily and stably stacked.

The central flexible portion 33 of the stopper is held to the outer piece 31 by the provision of a tongue 37 formed in outer piece 31 and a corresponding groove 38 is formed in the flexible portion 33. The flexible portion 33 is further extended at 39 to further increase its ability to be held by the outer piece 31 when the stopper is removed from the container. Other means may be used to hold the flexible portion to the outer piece such as a layer of adhesive in which case the flexible portion need not extend through the rigid outer piece. It is particularly advantageous, however, that the flexible portion 33 extend through the top of the outer piece 31. In this way, holes may be bored with conventional laboratory borers to enable glass tubing to be inserted through the stopper.

The outer skirt 32 preferably extends downwardly to a point where it is close to intersection 15 between the neck area and the body portion 14. In this way, the protective skirt prevents contamination from dust and other powders often found in chemical labs. This protection extends well past the upper lip and spout areas since it further protects the outer surface of the flared portion and the neck area.

The configuration of the stopper is shown in FIG. 4 in plan view with a part of the flexible portion 33 broken away. Openings 40 and 41 are formed in ridge 37 and the corresponding part of groove 38 is filled in so that it locks the flexible portion 33 in a non-rotatable relationship with the outer piece 31. In this way, the flexible portion 33 may be rotated to facilitate the insertion or removal of the stopper from the container.

Turning now to FIG. 5, there is shown an alternate configuration of the flared portion 50. Flared portion 50 is frustro-conical in shape which serves to support a conical filter medium much the same way that a conical funnel will support the medium. The angle formed by the two sides of flared portion 50 is 58 whereas the angle of the filter paper 51 is shown at 60. In this way, a minimum of filtrate is blocked by contact with the flared portion. It is further contemplated that downwardly pointing indentations or raised portions be provided in flared portion 50 to further decrease the contact between a filter paper 51 and flared portion 50. Such indentations or raised portions should not extend past the plane of minimum inside diameter 52.

Although the angle of the flared portion 50 of FIG. 4 is preferably 58 it may be varied between 50 and and still function effectively. Typically a funnel would not be effective over such a wide range of angles and the ability of the container of FIG. 4 to do this results from the relatively large minimum inside diameter as compared with a funnel. Note that there is no contact between the container and the filter paper 51 below the bottom of the frustro-conical portion of the container. In this way the liquid may freely flow through the filter paper and is not blocked by contact with a typical conical funnel.

Circular filter paper having a diameter of 11 centimeters is commonly used in chemical laboratories. A container useful for this size paper should have a body diameter between 1 a and 5 inches and a minimum inside diameter at its neck between one-quarter and three-fifths of its outside diameter. The overall height of the container is not critical.

By way of example, a container was fabricated according to the present invention for use with l l centi meter filter paper folded into a conical shape in the manner described above. Referring to H6. 1, the outside diameter 22 was 2 inches and the minimum inside diameter was 1 /2 inches. The outside diameter of the circular portion of the upper lip 17 was 2.29 inches and the overall height of the container was 6.946 inches. The height from the base to the plane of minimum inside diameter 16 was 6.357 inches. The wall thickness was 0.050 inches.

A stopper was fabricated having an outer piece molded from polypropylene and an inner flexible portion molded from natural rubber with a 50 durometer hardness. The outer protrusion indicated by the reference character 35 in FIG. 3 had an outside diameter of 1.54 inches. The inside diameter of the hollowed out area was 1.10 inches and the hollowed out area 34 had a height of 0.50 inches. The distance from the bottom of the flexible portion of the stopper to its top was 1.40 inches.

The combination of the stopper and container of the present invention results in a particularly effective piece of laboratory apparatus. Note that this combination takes the place of a series of conventional laboratory equipment. It is no longer necessary to support a funnel over a container or to transfer a filtered liquid from a beaker to another container which may be readily stoppered. Still further it was often necessary to place an additional protective cover over a stoppered beaker to decrease the chance for contamination of the unprotected lip area. The flared portion of the container is designed such that it is capable of supporting conventional filter paper containing the heaviest liquids without falling below into the container. Unlike Erlenmeyer and Florence flasks the container of the present invention may be both readily cleaned and its contents may be stirred or otherwise treated readily by insertions of spatulas or the like. The flared portion of the container facilitates the pouring of powders into the container.

While the container has been referred to as being fabricated from glass, it could, of course, be fabricated from another material such as plastic. The present embodiments of this invention are thus to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims therefore are intended to be embraced therein.

What is claimed is:

1. A container for use in filtering liquids capable of supporting a filter medium and also capable of containing the resulting filtrate comprising:

a body portion having a base which permits the container to stand in an upright position on a horizon tal surface;

a circular neck area integral with said body portion and located thereabove, the minimum inside diameter of said neck area being at least two-fifths of the maximum outside dimension of said body portion but no more than three-fifths of said maximum outside dimension;

a flared area extending upwardly from said neck area and terminating in an upper lip opening, said lip opening having a pouring spout and having a maximum outside diameter less than the maximum outside diameter of said body portion;

flexible stopper means havings its lower end extending below said flared portion and contacting said neck area; and

cover means fabricated from a rigid plastic attached to the upper end of said flexible stopper means, said cover means having a protective skirt extending outwardly above and downwardly around the upper lip of said container and further downwardly therefrom to a distance so that it about touches the intersection of the body portion and the neck area of said container when said stopper is fully inserted in said container, said skirt being generally cylindrical and having an outside diameter about equal to the outside diameter of the body portion of said container.

2. The container of claim 1 wherein said minimum inside diameter is about one-half of said maximum outside dimension.

3. The container of claim 1 wherein the intersection of said flared area with any plane in which the vertical axis of said container lies forms an arc of a circle having a radius between one-fourth and two-thirds of said minimum inside diameter.

4. The container of claim 1 wherein said flared area is frustro-conical in shape and the angle formed by the sides of said flared area is between 50 and 5. The container of claim 4 wherein said angle is about 58.

6. The container of claim 1 wherein said body portion is cylindrical.

7. The sealed container of claim 1 wherein said cap further has an indented area in its upper surface said indented area being shaped to mate with the base of said container.

8. A container for use in filtering liquids said container being capable of supporting a conically folded piece of 11 centimeter filter paper and further being capable of containing liquid said container comprising:

a cylindrical body portion having an outside diameter between 1 A and 5 inches and having a base portion which permits the container to stand in an upright position on a horizontal surface;

a neck area having a circular cross-section at any horizontal plane, the minimum inside diameter of said neck area being between two-fifths and threefifths of its outside diameter;

a flared area extending upwardly from said neck area and terminating in an upper lip opening having a maximum outside diameter less than the outside diameter of said cylindrical body portion and greater than said minimum inside diameter;

flexible stopper means having its lower end extending below said flared area and contacting said neck area; and

cover means fabricated from a rigid plastic attached to the upper end of said flexible stopper means, said cover means having a protective skirt extending outwardly above and downwardly around the upper lip of said container and further downwardly therefrom to a distance so that it about touches the intersection of the body portion and the neck area of said container when said stopper means is fully inserted in said container, said skirt being generally cylindrical and having an outside diameter about equal to the outside diameter of the body portion of said container.

9. The container of claim 8 wherein the cross-section of said flared area along any plane in which the central vertical axis of said container lies forms the arc of a circle having the radius between one-fourth and twothirds of its minimum inside diameter.

10. The container of claim 8 wherein said flared area is frustro-conical in shape and the angle formed by the sides of said flared area is between 50 and 11. The container of claim 10 wherein said angle is about 58. 

1. A container for use in filtering liquids capable of supporting a filter medium and also capable of containing the resulting filtrate comprising: a body portion having a base which permits the container to stand in an upright position on a horizontal surface; a circular neck area integral with said body portion and located thereabove, the minimum inside diameter of said neck area being at least two-fifths of the maximum outside dimension of said body portion but no more than three-fifths of said maximum outside dimension; a flared area extending upwardly from said neck area and terminating in an upper lip opening, said lip opening having a pouring spout and having a maximum outside diameter less than the maximum outside diameter of said body portion; flexible stopper means havings its lower end extending below said flared portion and contacting said neck area; and cover means fabricated from a rigid plastic attached to the upper end of said flexible stopper means, said cover means having a protective skirt extending outwardly above and downwardly around the upper lip of said container and further downwardly therefrom to a distance so that it about touches the intersection of the body portion and the neck area of said container when said stopper is fully inserted in said container, said skirt being generally cylindrical and having an outside diameter about equal to the outside diameter of the body portion of said container.
 2. The container of claim 1 wherein said minimum inside diameter is about one-half of said maximum outside dimension.
 3. The container of claim 1 wherein the intersection of said flared area with any plane in which the vertical axis of said container lies forms an arc of a circle having a radius between one-fourth and two-thirds of said minimum inside diameter.
 4. The container of claim 1 wherein said flared area is frustro-conical in shape and the angle formed by the sides of said flared area is between 50* and 70*.
 5. The container of claim 4 wherein said angle is about 58*.
 6. The container of claim 1 wherein said body portion is cylindrical.
 7. The sealed container of claim 1 wherein said cap further has an indented area in its upper surface said indented area being shaped to mate with the base of said container.
 8. A container for use in filtering liquids said container being capable of supporting a conically folded piece of 11 centimeter filter paper and further being capable of containing liquid said container comprising: a cylindrical body portion having an outside diameter between 1 1/2 and 5 inches and having a base portion which permits the container to stand in an upright position on a horizontal surface; a neck area having a circular cross-section at any horizontal plane, the minimum inside diameter of said neck area being between two-fifths and three-fifths of its outside diameter; a flared area extending upwardly from said neck area and terminating in an upper lip opening having a maximum outside diameter less than the outside diameter of said cylindrical body portion and greater than said minimum inside diameter; flexible stopper means having its lower end extending below said flared area and contacting said neck area; and cover means fabricated from a rigid plastic attached to the upper end of said flexible stopper means, said cover means having a protective skirt extending outwardly above and downwardly around the upper lip of said container and further downwardly therefrom to a distance so that it about touches the intersection of the body portion and the neck area of said container when said stopper means is fully inserted in said container, said skirt being generally cylindrical and having an outside diameter about equal to the outside diameter of the body portion of said container.
 9. The container of claim 8 wherein the cross-section of said flared area along any plane in which the central vertical axis of said container lies forms the arc of a circle having the radius between one-fourth and two-thirds of its minimum inside diameter.
 10. The container of claim 8 wherein said flared area is frustro-conical in shape and the angle formed by the sides of said flared area is between 50* and 70*.
 11. The container of claim 10 wherein said angle is about 58*. 